1. Field of the Invention
The present invention relates in general to an engine cooling system of the type wherein the coolant is boiled, so as to make use of the latent heat of vaporization thereof, and coolant vapor used as vehicle for removing heat from the engine, and more particularly to an improved parts-arrangement therefor.
2. Description of the Prior Art
Hitherto, a so-called "boiling liquid cooling system" (viz., evaporative cooling system) has been proposed for achieving cooling of a combustion engine, such as internal combustion engine. This type cooling system basically features an arrangement wherein a liquid coolant (for example, water or a mixture of water and antifreeze or the like) in the coolant jacket of the engine is permitted to boil and the gaseous coolant thus produced is passed out to an air-cooled heat exchanger or radiator where the gaseous coolant is cooled or liquefied and then recirculated back into the coolant jacket of the engine. Due to the effective heat exchange carried out between the gaseous coolant in the radiator and the atmosphere surrounding the radiator, the cooling system exhibits a very high performance.
However, as will become apparent hereinafter, some of the cooling systems of the type as mentioned hereinabove have not taken any measure to counter cold weather. Thus, in cold season, they sometimes induce abnormal or incomplete operation thereof particularly at warm-up stage of the engine due to freezing of the coolant in the system.